Any activation conditions (written before the colon) only have to be met when you activate the card. (Any conditions that STILL have to be true when the effect resolves will be listed separately.) (Article 4)

refers to a ‘target’, you have to double-check that any targeting requirements are still met.

refers to the target using any other word (like ‘it’), the targeting requirements only had to be met when the target was originally targeted.

refers to ‘both’ (or a similar term) in the effect text, you have to be able to apply the effect to ALL of the targets. If even one of the targets is no longer eligible, then the whole effect disappears.